When you have high income, it is true that "pre-tax" retirement savings almost always results in lower overall taxes paid (today's + during retirement). So at that level, you should focus your retirement dollars into either a pre-tax work plan or (if you have no retirement option through an employer) a Traditional IRA. The income restriction on deducting tIRA contributions only applies when you also have a work plan.

But there's a limit to how much pre-tax "space" you're allowed to use. Some people want to put away a lot for their retirement each year, more than they're allowed with regular 401k contributions. Maybe they're behind for their age, maybe they want a fancier lifestyle, maybe they just have no better use for those dollars. So while the tax cost from saving in a Roth may not be ideal, it still could be the best option compared to some non-tax-advantaged account. But again, only after "using up" all your available pre-tax options.

>Currently I'm still below the Roth IRA contribution limit
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>...
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>I'm currently in the second highest tax bracket

These two statements are not compatible. The income cutoff where your allowed direct Roth IRA contributions becomes $0 is roughly 1/3rd of the way into 24% tax bracket (give or take a bit between the filing statuses). If you're in the 35% bracket, then you make way too much to use a Roth IRA without the backdoor.